Liquid conductor heater



April 3, 1951 M. w. HANKs LIQUID CONDUCTOR HEATER 3 Sheets-Sheet 1 Filed May 17, 1947 x "han" April 3, 1951 M. w. HANKS LIQUID CONDUCTOR HEATER 3 Sheets-Sheet'. 2

Filed May 17, 1947 April 3, 1951 M. w. HANKs 2,547,865

LIQUID CONDUCTOR HEATER Filed May 17, 1947 5 Sheets-Sheet 5 13u/enf@ n Mars/QM M@ n Patented Apr. 3, 1951 UNITED STATES PATENT OFFICE LIQUID CONDUCTOR HEATER Marshall W. Hanks, Madison, Wis., assignor to Hankscraft Company, Madison, Wis., a corporation of Wisconsin Application May 17, 1947, Serial No. 748,790

(Cl. 21S-40) 12 Claims. 1

Y have been described and claimed in numerous Letters. Patent of the United States taken out by me including, for example, No. 1,683,069, dated September 8, 1928, No. 2,051,837, dated November 24, 1936, and No. 2,369,891, dated November 3, 1942.

Liquid conductor heaters of this type have been highly successful in practical use but have had the disadvantage of slow starting because it has been necessary to heat the entire body of water in the vessel before vaporiaztion begins. Further, the steam generated at the electrodes condenses and imparts its heat to the adjoining liquid by which it is transmitted to the main body of liquid so that there is some loss of efficiency. Also, in most devices of the type referred to there is a tendency for the development of a large starting current which continues until the resistance of the liquid is increased by' the formation of a bubble structure between the electrodes.

The principal object of the present invention is to improve upon prio-r devices of this type in the foregoing respects, and others, by providing apparatus in which evaporation is started and maintained by heating only a small portion of the total quantity of water in the vessel and in which the condensate returns directly to the electrodes for re-evaporation without circulating through the mainA body of liquid, thus providing a quick acting and more eflicient operation. A further object is to provide a liquid conductor heater in which the spaced electrodes are located partially or wholly outside the body of liquid in the vessel and liquid is conveyed to the electrode portions outside of the liquid body by capillary action through a porous body or wick formed preferably of non-conducting, non-carbonaceous material, such as glassV wool, asbestos or the like, whereby a quick acting vaporization is initiated and maintained, without directly heating the many body of liquid at all or without directly heating any substantial portion thereof. Still another object of the invention is to provide a' liquid conductor heater comprising an insulat-i ing vessel adapted to contain a body of liquid and having mounted therein a tubular insulating member containing a body of capillary ina sulating material extending into said liquid and contacting with two upwardly extending spaced electrodes formed preferably as intermeshing coaxial helices of conducting material having their upper ends arranged for connection in an electric circuit. Other objects relate to various feav tures of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which several embodiments of the invention are illustrated. In the drawings,

Figure 1 shows a top plan View of one form of liquid conductor heater embodying the features of the present invention;

Fig. 2 shows a vertical section taken on the line 2-2 of Fig. 1;

Fig. 3 shows a top plan view of a second form of the invention;

Fig. 4 shows a vertical section taken on the line 4-'4 of Fig. 3;

Fig. 5 shows a top plan View of a third form of the invention;

Fig. 6 shows a vertical section taken on the line 6-6 of Fig. 5;

Fig. 7 shows a top plan View of a fourth form of the invention;

Fig. 8 shows a vertical section taken on the line 3-8 of Fig. 7; l

Fig. 9 shows a top plan view of still another' prising a vessel l0 formed of insulating material,v such as porcelain or the like, and containing'aj body of water or other liquid Il which is tobe v aporized when the device is in operation. The vessel l0 has a cover l2 in which there is mounted a tubular member i3 formed of insulating material and having positioned therein a body I4 of capillary material such as glass wool, asbestos, or

the like, which is non-conductive and non-carbonaceous, through which the water Il is con-l veyed upwardly by capillary action into contactg provided with a central aperture la through`r which the vapor produced by the passage of current between the convolutions of the electrodesv escapes to the atmosphere.

The terminal posts Iau are adapted to be connected in an electric circuit by means of the usual plug and electric cord and when they are connected in the circuit the portions of the liquid whichlarei-n the bod-y of the capillary material I4 are vaporized by the passage of the electric current therethrough. In the form of the invention shown in Figs. l and 2, the'c'apillary material I is arranged in tubular fashion around the convolutions of the two electrodes I5 which are coaxial with each other and coextensive with the walls of the tube I3. Both th'e tube I3 and the capillary material ifi 'extend downwardly into the body of Water I i and the tubular formation of the capillary material Iii provides a passages Illa at the bottom of the tube through which the water extends upwardly to a point in proximity to the electrodes, from which point the liquid is conveyed by capillary action to the portions of the electrodes which contact with the material I4. With this arrangement of the" parts, there is an instant starting of the device when it is connected in the electric circuit and the vapor condensate in the upper part of the tube falls back into contact with the convolutions of the electrodes or spatters onto the adjacent walls by the action of the bursting bubbles so that it is againimmediately vaporized without returning to the mainvbody of liquid I i in the bottom of the vessel. The vaporization of the liquidmay be continued for a substantial period of time without replacing the body of liquid in the Vessel and Without the necessity of heating the entire body of liquid. It has been found in practice that the electrodes I5 have a longer life if the convolutions of the electrodes have a graduallyA increasing spaced relation from their lower ends upwardly and that arrangement is therefore preferred. Although illustrated asl embodied in a vaporizer which may be used for,

medicinal purposes, it will be apparent that the principles of this invention may be embodied in liquid conductor heaters used for cooking, bottle warming, and other like purposes.

`In the form of the invention shown in Figs. 3 and 4, a vessel 2i) contains a body of water or other liquid 2l and is provided with a cover 22 arranged to carry a depending tube 2-3, formed preferably ofv insulating material, in which there is mounted a body of capillary material 24 such as glass wool,

parallel relationship through the cap member 26,

of insulating material which ts into the upper end of the tube 23. This cap member :26 has a central aperture 26a to allow the escape of the vapor which is produced by the passage ofc'ur rent between the convolutions of the electrodes when the terminal posts 25a are pluggedinto van electric circuit.

In the form of the invention shown in Figs. 3 and 4, the tube 23 is restricted at its lower end asshown at 2.3"- and the capillary material is correspondingly compressed to form a solid body 24e of this material within the restricted part of the tube. The part 23 of the tube and the material 24a contained therein extend downwardly into the body of the liquid 2I to a point adjacent the bottom of the vessel. The operation of this form' of the invention is generally similar to that previously described except that there is no open body of water within the tube adjacent the lower parts of the electrodes. It has been found in practice that the device will operate successfully even though the lower ends of the electrodes are spacedsubstantial distances above the level of the liquid in'the'vessel, the distance depending largely upon the capillary action of the particular material employed in contact with the electrodes. In this form, the restricted tube 2.3*JL may not be occupied by capillary material but the small short tube serves to cut down leakage curz rent vand thereby minimize the danger of shock in case the fingers of the operator come in contact.. with the tube when the entire unit is removed: from'the vessel 2Gwith-the electriccord still at-.x

The form of 'the invention shown in Figs. 5 and 6 is generally similar to those previously described except that the body of capillary material is enclosed within the convolutions of the electrodes:` In this form, the' insulating vessel Sil is adapted to contain azbodyf: fof vwater or other liquid 3l and is provided with" a cover 32 which is arranged to support a tube 33, formed preferably of insulating material, which' instead of surrounding them.

extends downwardly into the liquid 3lv and terminates slightly above the bottom of the vessel. The tube 33 contains a body of capillary material"` 34, such as glass wool, asbestos or the like, whichoccupies the entire area of the lower part of the tube below the surface of the liquid SI but which has its upper portion restricted or compressed in cross section to provide a cylindrical extension 34e volutions of the electrodes through the portions of the liquid which are conveyed thereto by capillary action, will escape through the aperture 36a to the atmosphere, so that it may be employedA for medicinal purposes or the like. As in the two formsof the invention previously illustrated, the

convolutions of the electrodes may preferably have an increasing spaced relation as the upper end of the device is approached,

Another form of the invention is shown in Figs.-v 7 and 8 and it differs primarily from those pre-` viously described in that the capillary material isi preferably omitted and the convolutions of the electrodes extend downwardly into the body of the liquid. As there illustrated, this form ofthe invention comprises a vessel 43 formed of in, sulating material and containing a body of water or other liquid 4I. The vessel has a cover A2, which is arranged to support a tube i3 formed of insulating material and extending downwardly intothe body ,of liquid Mfwithits ends spaced slightly above the bottom of the vessel. In the tube I3 there are mounted two metallic electrodes '45 having helical convolutions 45a rwhich lntermesh with each other and are .spaced `apart so that adjacent convolutions `are of opposite polarity. These Ielectrodes have their upper ends formed as terminal posts l5b Awhich project through the insulating cap j4I; fitting within Vthe upper end of the tube 43 and having a central aperture '46a for the escape of vapor. 'In this form of theinvention, the starting of the vaporization and the continuance thereof are not `dependent upon capillary action. When the terminal posts 155b are plugged into an electric circuit, the inissagev of current through the body of liquid Within the lower end of the tube 43 between the convolutions of 'the electrodes which are immersedlin this portion of the liquid will cause the vaporization thereof with a resulting bubble formation which will extend upwardly within the tube and thus cause electric connections to be lformed between the upper convolutions of the electrodes. In this "way, the zone vof activity is increased in height so that the vaporizaton of the liquid will be carried 4on at an increased rate after the initial starting has been effected,` which is in contrast with the operation yof the usual liquid conductor heater where the starting current tends to be larger than the running fourrent. As in the forms ofthe invention previously described, the condensate which forms in the upper part of the tube .falls downwardly and is again evaporated by 'contact with lspaced convolutions of the electrodes without returning to 'the body of liquid in the vessel. f

The form `of the invention illustrated in Figs. 9 and lOvembodies the features heretofore described but the structure is somewhat more `commercial in form and comprises an arrangement wherefthe spaced helical electrodes have 'their lower ends immersed in the body of liquid in ythe vessel and have liquid conveyed to the upper vconvolutions thereof by capillary action. As there illustrated, this last embodiment of the invention comprises a vessel 50 formed of insulating material and arranged and arranged to contain a body of `water or other liquid i which `is to be vaporized The upper'end of the vessel 50 is restricted in size and is externally threaded for engagement by a member 52. The member 52 is centrally .apertured to receive a hollow inverted cap member 53 `formed of porcelain, Bakelite, or other in'sulatingrlmaterial and having an outwardly extending iiange .53a which engages the upper surface of the cover 52 around its central aperture. 'Within the cover member, the lower externally threaded portion 53b of thecap member 53 is engaged 'by an annular clamping ring 54 which secures in place an 'insulating sleeve 55 .and .also a tube 56. 'Thefinsulating sleeve 55 is provided with an outwardly extending annular iiange 55a and a ring l'of .r'fbber or other packing material is vpositioned between' the iiange 55aL vand the lower .end .of the part 53h of the cap member. The upper end of the tube 56 surrounds the lower end of .the insulating sleeve 55 and is provided with 1an outwardlyturned annular iiange '5Sa which is engaged on its underside .by the inwardly ,directed annular flange 54Sa which .is formed lon the lower end lof the clamping rin-g 54- When the-member 54 .is' screwed to its .normal position shown in Fig. l0, the annular ange 4541-11 the upper end thereof clamps the cover member 52 against the flange 53a of the cap .member and at the same :flans-e. 54a, clampsibe .members 5,-31 and 55a together to effect `a compressonof the .ntervening gasket 5l..

The tube 56 extends downwardly into the body of .liquid 5|, terminating :adjacent the :bottom of the vessel, and it contains a tubular body l58 of capillary material such las glass wool, asbestos, or the like, which has mounted therein the intermeshing helical convolutions 59-u of the electrodes 59. These electrodes terminate at their upper ends in straight portions 59lo which extend through the insulating sleeve 55 and are ysecured at Vtheir upper ends to terminal ttings 6D which are mounted within the hollow cap member .53. These fittings are provided with terminal posts El which .extend downwardly through the vertical wall 53c of the cap member ifor engagement with the plug -62 of an electric circuit. `The insulating sleeve 55 has formed therein a central aperture 55D to permit the escape of vapor Afrom the region of the convolutions of the electrodes. This `aperture 55b communicates with the internal chamber of the ycap member .53 .and one `wall of this cap member is provided with an aperture 53d through which the vapor escapesV 4to the .atmosphere. The cover member 52 is provided at one Vside with an aperture normally closed .by a removable insulating plug 63 so that the ,supply of medicant or other liquid within the vessel may be replenished without removing the cover 52.

In the operation of the form of the .invention shown in Figs. 9 .and 10, the vaporization is `initiated by the passage lof current betweenV Athe lower convolutions rof the velectrodes which are immersed in the body of the liquid 5I 'and is continued and maintained not only vby this vaporization but .also by the vaporization lof liquid Awhich connects the upper convolutions of the .electrodes after passing by capillary action through the material 58 land by the .bubble formation which arises within the convolutions due to the boiling of the liquid within the lower vconvolutions of the electrodes. The condensate which :is vormed in the upper part of the 'heating device and inthe passages leading to the orifice y53d returns to the chamber in which the convolutions oi the electrodes are located Aand is 'vaporized without again intermingling with the body of the liquid in the lower :part :of the vessel.

It has been found that the form of Athe invention shown in Figs. 11 and 12 tends to minimize any danger vof the electrodes burning out at the top of the coils, a tendencv which sometimes develops :in devices of this kind, This is accomplished by :feeding the Awater te lthe electrodes at their tops .instead of at their lower ends through the use of an inner vessel in which the electrodes are located. In this `form the outer insulating vessel 65 is adapted to contain a body of .liquid 65 in vwhich .is `partially immersed the lower end of a tube El which is suspended from the cover '68.

An insulating nlug 69 is inserted in the upper end of the tube 61 and has mounted therein the terminal portions 18a of two spaced electrodes '10.. The lower parts of these electrodes are vhelical in form and intermesh with 'each :other in Yspaced relation 'within an inner vessel "12. The vessel l2 is surrounded and supported bv .a bod-v of capillary material T3 which rests on the lower wall 65a of the tube BT 'which restricts the tube so that it 'has a comnarativelv small bottom opening h. The capillary material 'i3 extends over the top edge of the vessel l2 and downwardly withinthis vessel aroundand below the helical electrodes. Thus, the liquid 66 which nds its way upwardly through the capillary material finds its way rst to the upper parts of the electrodes and passes progressively downward within the vessel 12.

Although certain forms of the invention have been shown and described by way of illustration,

it will be understood that it may be constructedv passage for the escape of vapor from said elec-v trodes.

2. In a liquid conductor heater, an insulating' vessel adapted to contain a quantity of liquid, spaced electrodes mounted in said vessel above the body of liquid therein, a non-conducting member extending into said liquid and adapted to convey liquid to said electrodes by capillary action, and means forming an unobstructed passage for the escape or vapor from said electrodes. 3. In a liquid conductor heater, an insulating vessel adapted to contain a quantity of liquid, spaced electrodes mounted in said vessel and comprising helical convolutions interrneshing with each other in spaced relation, and a body of non-conductive material extending into said liquid and arranged to convey liquid to convolutions of opposite electrodes by capillary action, said non-conducting material and said convolutions being arranged to provide an unobstructed passage from said electrodes to permit the es cape of vapor.

4. In a liquid conductor heater, an'insulating vessel adapted to contain a quantity of liquid, spaced electrodes mounted in said vessel and comprising helical convolutions intermeshing with each other in spaced relation, and a body of non-conductive material extending into said liquid and arranged to convey liquid to convolutions of opposite electrodes by capillary action, said convolutions having an increasing spaced relation as their distance from the body of liquid increases;

5. In a liquid conductor heater, an insulating vessel adapted to contain a quantity of liquid, a tube located in said vessel and extending downwardly into said liquid, a pair of upwardly extending spaced electrodes mounted in said tube,- and a body of non-conductive material mounted in said tube and adapted to convey liquid to said electrodes by capillary action, said tube and said material being arranged to form an unobstructed passage for the escape of vapor directly from said electrodes.

6. In a liquid conductor heater, an insulating vessel adapted to contain a quantity oi liquid', a tube located in said vessel and extending downwardly into said liquid, a pair of upwardly extending helical electrodesmounted in said tube with their convolutions intermeshing and spaced apart, and a body of non-conductive material mounted in said tube and extending into said liquid and adapted to convey liquid to said elec-i trodes by capillary action, said convolutions having an increasing spaced relation as their upper ends are approached.

v'7. In a liquid conductor heater, an`insulating vessel adapted 'to contain a quantity ofliquid,a

tube located in said vessel and-extending downwardly into said liquid, a pair of upwardly extending helical electrodes mounted in said tube with their convolutions intermeshing and spaced apart and a body of non-conductive materialmounted in said tube and extending into said liquid andv adapted to convey liquidl to said elecv trodes by capillary action, said tube being provided at its upper end with means for permitting. the-escape of vapor, said tube and said materia-1 being larranged to forman unobstructed passage. for the escape of vapor directly from said electrodes;

8. In Aa liquid conductor heater,l an insulating vessel adapted to contain a quantity of liquid, a,.- cover for said vessel having an aperture therein,v

a hollow cap-member engaging said aperture andy having a ilange overlying -said cover, an insu-v lating sleeve engaging the lower part of said cap member -andhaving-a ange underlying the lower end oisaid cap member, a tube extending downwardly into said liquid and having a flange.

underlying said -iiange on said sleeve, and a clamping member for securing said capv member toA said 'cover' and for securing said sleeve and.

having a flangeoverlying said cover, an -insulating sleeve engaging the lower part of saidv cap member andhhaving a flange underlying the lower end of said cap member, a tube extending downwardly into said liquid and having a flange underlying said flange on said sleeve, a clampingv memberfor securing said cap vmember tosaid, cover andfor securing-said sleeve and said tube to said cap member, spaced electrodes carried by,V said sleeve and'extending. downwardly into said tube, and non-conductive material for conveying liquid upwardlyby capillary action to said electrodes.

l0. In a liquid conductor, an insulating vessel adaptedto contain a quantity of liquid, a tube.A mounted vin said vessel and extending downwardly into said liquid, a pair of spaced elec trodes mounted within said tube, a'body of non-' conductivecapillary material mounted in'said tube and extending into said liquid, and means, for causing the liquid passing through said cap-J illary material tofnd access first to the upper ends of said electrodes, 11. In a liquid conductor, an,insulatingvvessel adapted to contain a quantityof liquid, atube mounted in said vessel and extending downwardly into said liquid, a pair of spaced electrodes. mounted within said tube, a body of non-v conductive capillary material mounted in said tube and extendingrinto said liquid, and a second vessel mounted insaid tube and containing, said electrodes, said capillary material extending into said second vessel over the upper end thereof whereby said liquid is caused to connect said electrodes progressively downward from the upper ends thereof. j

12. In aliquid conductor heater, an insulating vessel adapted to contain a quantity of liquid,v tube mounted in said vessel and extending down-A wardly into the bodyv of liquid therein,a pair of spaced electrodes located in said vessel above the4 level wof said' liquid, and a body of non-condu'cf' tive material mounted 'in said tube in, contact with said electrodes and extending downwardly into saidiliqui'dto convey said liquid lt`o said elec-y trodes by capillary action, the portions of said tube and of said non-conductive material within said liquid being reduced in cross section as compared with the parts thereof above said liquid.

MARSHALL W. HANKS.

REFERENCES CITED The following references are of record in the le of this patent:

Number Warren Oct. 14, 1947 

